Electrostatic interactions disproportionation

In the framework of LEA, the electrostatic interactions manifest themselves through the entropy of ions disproportionated between the interior of a strongly branched macromolecule and bulk solution. Therefore, the driving force for swelling of a branched polyion can be formulated in terms of the differential osmotic pressure of small ions inside and outside of the macromolecule. 

It needs to be noted that Q + Q = Q + equilibrium is possible due to the rapid consumption of Q reducer. More often, the interaction of two identical ion-radicals can lead to their dimerization, but not disproportionation. For instance, the anion-radicals of tetracyanoethylene undergo dimerization (Lu et al. 2003). According to Miller and Novoa (2007), this dimerization proceeds as four-center carbon-carbon bonding. Rosokha and Kochi (2007) proposed the term n interaction for dimerization of the cation-radicals of tetrathiafulvalene. Because the n dimers are double-charged species, solvent polarity is essential for their formation. The n interaction overcomes the electrostatic repulsion, even in moderately polar enviromnents. 

For all reactions (2) with at least one component uncharged, AG = 0 if, as is normally done, we exclude dipole-dipole interactions. This means that AGf can be neglected for many organic electron-transfer reactions. Otherwise, in media that are often used for organic redox reactions the electrostatic effects are formally fairly large and certainly not negligible. The effect of cations upon the disproportionation of radical anions (41) in ethereal media is an example of... 

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